| Message ID | 1398161174-9247-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c index caeb8d6..4676917 100644 --- a/drivers/usb/core/hcd-pci.c +++ b/drivers/usb/core/hcd-pci.c @@ -75,7 +75,7 @@ static void for_each_companion(struct pci_dev *pdev, struct usb_hcd *hcd, PCI_SLOT(companion->devfn) != slot) continue; companion_hcd = pci_get_drvdata(companion); - if (!companion_hcd) + if (!companion_hcd || !companion_hcd->self.root_hub) continue; fn(pdev, hcd, companion, companion_hcd); }
This is a note to let you know that I have just added a patch titled USB: fix crash during hotplug of PCI USB controller card to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 60b6ec84fb43ad5a3cd2202219a913ad25a353e4 Mon Sep 17 00:00:00 2001 From: Alan Stern <stern@rowland.harvard.edu> Date: Mon, 14 Apr 2014 13:48:47 -0400 Subject: USB: fix crash during hotplug of PCI USB controller card commit a2ff864b53eac9a0e9b05bfe9d1781ccd6c2af71 upstream. The code in hcd-pci.c that matches up EHCI controllers with their companion UHCI or OHCI controllers assumes that the private drvdata fields don't get set too early. However, it turns out that this field gets set by usb_create_hcd(), before hcd-pci expects it, and this can result in a crash when two controllers are probed in parallel (as can happen when a new controller card is hotplugged). The companions_rwsem lock was supposed to prevent this sort of thing, but usb_create_hcd() is called outside the scope of the rwsem. A simple solution is to check that the root-hub pointer has been initialized as well as the drvdata field. This doesn't happen until usb_add_hcd() is called; that call and the check are both protected by the rwsem. This patch should be applied to stable kernels from 3.10 onward. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Stefani Seibold <stefani@seibold.net> Tested-by: Stefani Seibold <stefani@seibold.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/usb/core/hcd-pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.9.1